Mount for electron-emission devices



Dec. 28 1926.

H. DE F. MADDEN MOUNT FOR ELECTRON EMISSION DEVICES Filed Sept. 29, 1922 INVENTQR HARRY 0. MADDEN I A ORNEY Patented Dec. 23, 1926.

- UNITED STATES HARRY DE FOREST MADDEN, OF NEWARK,

NEW JERSEY, ASSIGNOR TO WESTING HOUSE LAMP COMPANY A CORPORATION OF PENNSYLVANIA.

MOUNT FOR ELECTRON-EMISSION DEVICES.

Application filed September 29, 1922. Serial No. 591,207.

This invention relates to the manufacture of electron-emitting devices, such as radiotrons or the like.

An object of the invention is to provide mounts for electron-emission devices in which the elements may be expeditiously and convenientlyassembled for union in desired relative positions.

7 Another object of the invention is to facilitate the assembly of the elements constituting an electron-emission device, such as a radiotron, to provide a more accurate disposition of the elements prior to their union p and to maintain their desired relative position's after union.

A further object of the invention is to provide a mount for a radiotron, the parts of which may be assembled by an operator the exercise of a minimum amount of Other objects and advantages will be apparent from the following description.

This invention has special application to electron-emission devices used in connection with radio equipment-- and which usually comprise a bulb in which is sealed at mount, the bulb being evacuated by any suitable means. Devices of the above character have become generally known in the art as radiotrons. Y

The mount, which constitutes the internal structure of a radiotron, generally comprises a cathode or filament positioned within a grid which, in turn, is surrounded by an anode or plate. These three elements are usually held in given relative positions by supports and by leading-in wires which are embedded in the press of what is termed a flare tube which constitutes One of the component parts of the mount.

It is of great importance, in the manufacture of radiotron mounts, to properly position the elements in a given relation particularly the grid and plate. For efficient service and practical working conditions, the grid and plate must be so disposed with relation to each other as to provide a symmetric space between them when they are mounted. The improper or unsymmetric positioning of the grid and plate, that is, in permitting the distance between the elements to vary from the desired symmetric relation, results in a non-uniform electron-emission which causes a deterioration of the filament and shortens the life of the device.

In the manufacture of a mount, the filamentand grid are secured, as by welding, to leadmg-in and support wires, respectively. These two elements may be disposed in a given relation by any suitable means. It has heretofore-been the practice to provide the plate with a plurality of projections or ears, preferably four, two on each end for connection to upwardly extending support wires which are secured and arranged in the press at approximately their position wlhen subsequently secured to the ears of the ate. i The operator, when securing the plate to these support else a considerable degree of skill to properly position the plate and must also train the support wires to such position as to maintain the plate in symmetric relation to the grid, particularly after the plate has been welded to the supports. To do this, it will be readily appreciated that the operator must bend the support wires to such positions that they will not return to other positions after release, by reason of any poential energy due to their resiliency.

It is not .always possible, however, for human agency to attain this desirable adjustment, especially since the operator may unknowingly bend the supports t6 positions from which they will return after the plate has been welded thereon. This reaction of the supports necessarily tends to move the plate and destroy any alignment the operator may have temporarily attained. It is, therefore, necessary, after the welding operation, toagain inspect and properly align the plate by bending the support wires until the proper symmetric relation exists. Considerable skill is necessary, however, to accomplish this, inasmuch as the: support wires are relatively stiff and must be bent to positions slightly beyond those required in order to ensure their return to the required positions.

wires, necessarily must exer- My invention, therefore, provides a means for properly adjusting a plate'in such relation to support wires that no lateral stress is imposed upon the supports to produce an ultimate change in their relation after they have been manually aligned and welded in position.

To accomplish the above, I provide a plate upon which extensions may either be welded or be formed as integral portions bent outwardly' therefrom. The projections or studs may be disposed at the normal vertical ends of the plate and midway between the upper and lower edges thereof. The studs may, therefore, serve as pivot points and, for the purpose of providing seats or hearing surfaces for these studs, I may provide the support wires with portions bent at right angles to the vertical axis of the wire and of such proportions that, when the plate is disposed in its proper Vertical relation to the grid, the studs will bear upon the horizontal surfaces.

It will, therefore, be appreciated that a plate may be disposed over a grid and adjusted along the horizontal surfaces until it takes the proper symmetric relation to the grid. In addition to this lateral or partial rotary movement of the studs along the horizontal surface, the plate may be tilted to vary the position of the vertical axis of the plate, which may be necetsary to make it coincide with the axis of the filament and universal adjustment'provided by the present invention is of great importance. The extensions orv lugs may have cylindrical or half-round bearing surfaces and a plate maybe adjusted to give a symmetric spacing between the grid and the plate without any stress being applied to the supportwire, the adjustment being made by the disposition of the lugs along the horizontal surface and by tilting the plate.

The plate may thus be more readily aligned by the operator, however, I may provide also an insert or spacer member in the form of a jig adapted to be positioned between a grid and aplate prior to the union of these two elements by welding. Thus, a temporary means for accurately spacing the two elements is provided and, while this spacing element is in position, the lugs may be welded to the support wires and, since it is not necessary to bend or otherwise adjust the support wires, the spacer may be removed after welding without the possibility I of any displacements of the plate by a movevided.

ment of the support wires to other positions, as was the case in mounts heretofore pro- The invention will be more fully understood by reference to the accompanying drawings in which Fig. 2 is a side view, in elevation, of a radiotron mount;

Fig. 3. is a plan view of the device shown in Fig. 2;

Fig. 4c is an elevational view of a mount showing'thc spacer member positioned between the plate and the grid, the spacer member and the plate being shown in section;

Fig. 5 is a transverse cross section taken on line V-V of Fig. 4; and,

. Fig. 6 is a view, in elevation, of a radiotron as an example of a device to which my invention has been applied.

As illustrated, my invention is embodied in amount 10 which includes a flare tube 11 having relatively rigid support wires 12 and 13 one of which serves as a, conductor as well as leading-in wires or supports 14 and 15 embedded in a press 16 of the flare tube in the usual manner.

Secured to the upper ends of the leading in wires 14 is a'filament 17 which may have an additional supporting wire 18. The support wires 15 are welded to the lower end of a grid 19 in which the filament 17 is positioned. The grid and filament may be secured in their proper relation by the usual manufacturing operations.

A plate 20, which consists of what may be termed a section of a flattened tube, of the usual type, may be utilized. For the proper disposition of the plate 20, however, it may, in accordance with my invention, be provid-- edwith a pair of lugs or studs 21 and 22 which project from the normally Vertical ends 23 and 2 10f the plate. The upper ends of the support wires 12 and 13 are bent transversely to provide horizontal bearing surfaces 25 and 26 along which the studs 21 and 22 may be moved. When the plate is properly adjusted with respect to the grid, suitable welding jaws 27 and 28 may be manipulated to weld the studs and supports together.

When desirable, a spacer-member 29 may be employed, (see Fig. 4). This member is of such size and shape as to fit easily inside the plate 20, and the plate may he slipped over the spacer-member as shown. An aperture 31 is provided within the member of such cross sectional configuration as to permit the entrance of the grid therein. The depth of the aperture 31 may be of a proper dimension so that, when the spacer-member is inserted thereover, the upper ends of the grid may make contact with the end 32 of the aperture to bring the plate 20, when correctly positioned on the spacer, in proper vertical relation to the grid. The filament 17 may be secured to the support-.18 after the spacer-member 29 has been removed or the spacer-member may ave a suitable slot to permit the passage of t e horizontal portion 33 of the support 18.

x no

The spacer-member may remain in position until the welding jaws have been operated to secure the support wires 12 and 13 to the studs 21 and 22, respectively, after which the spacer-member may be removed, leaving the grid and plate in the desired spaced relation, depending upon the configuration of the spacer-member. It will be understood that, it it is desirable to have the space between the grid and plate equal at all points, the spacer-membermay be provided with a spacing wall properly proportioned or the mmeber may, it desirable, be provided with a spacing wall of unsymmetric proportions.

It will be evident that, with my invention, the manufacture of radiotron devices is greatly improved, particularly in that the operators work is less tedious and in that a greater output is possible.

Although I have shown and described a prefer-ed embodiment of my invention, it is to be understood that other modifications may be made therein without departing from the spirit and scope of the appended claims.

What is claimed is:

1. An electron-emission device comprising a plate having extensions, support members to receive said extensions and provide bearing surfaces therefor to permit temporary adjustment of the plate in at least two direc tions transverse to its longitudinal axis.

2. An electron-emission device comprising a plate having projections thereon and supporting-members provided with transverse bearing surfaces to permit a slidable adjustment and temporary support for said plate prior to the union of the plate and the supporting-members.

3. A mount for an electron-emission device comprising a grid, a plate having projections, supporting members for said plate having relatively long bearing surfaces to receive said projections, means for securing said grid in a given fixed position, aspacer member adapted to temporarily space a plate in a given relation to a grid, said projections and bearing surfaces serving to permit an adjustment of to a given position with respect to the other the plate and spacer member elements of the mount i. A mount for an vice comprising supports having portions bent transversely to the longitudinal axis of the mount, a plate having projections, said plate being adapted to be temporarily supported on said bent portions for adjustment to a given position and subsequently secured to said portions.

5. A mount for an electron-emission device comprising supports having portions bent transversely to the longitudinal axis of the mount, a plate having projections for engagement with said bent portions to permit the proper adjustment of the plate when the same 'is disposed with the said projections in contact with said bent portions for subsequent consolidation with the mount.

6. A mount for an electron-emission device comprising vertical supports bent to provide transverse portions and a plate havin studs, said studs being adapted to engage said transverse portion and to be move therealong, whereby a preliminary adjustment of the plate may be attained.

7. A mount for an electron-emission device comprising vertical supports having portions bent transversely, means for sup porting a filament and a grid and a plate having supporting studs whereby said plate may be adjusted to a given position and supported by an engagement between said studs and said transverse portions.

8'. The method of manufacturing a mount for an electron emission device having horizontal supporting surfaces, which comprises temporarily disposing a body about an element secured in the press of the mount, disposing a second element about the body, se-

curing said second element to said surfaces in accordance with its disposition as controlled by said body and removing said body.

In testimony whereof, I have hereunto subscribed my name this 28th day of September 1922.

HARRY DE FOREST MADDEN.

electron-emission de- 

